The present invention relates to a system for producing three light beams that are oriented on orthogonal, intersecting lines and, more particularly, to such a system in which power levels of the three beams are substantially equal. Systems of this type provide visible reference lines that can be easily seen, and that define the axes of a coordinate system for measurement and reference.
Laser beam projection devices have been used in the past to project three or more laser beams along orthogonal, intersecting lines. Such laser beams, preferably in the visible spectrum, define reference lines that are useful in construction projects for laying out dimensions in three directions. For example, such devices make it easier to lay out the position of walls, cabinets, doors, windows, and the like, in a building under construction.
Systems and devices of this type typically use a single laser diode as the light source, and divide the laser beam that the laser diode produces into three or more reference beams. Such systems and devices have typically been somewhat complicated in construction and, further, have provided reference beams of light that differ significantly in power level. It will be appreciated, however, that it is desirable that the reference beams are of substantially equal power. If one of the beams has significantly less power than the other beams, then the operating range of the device will be significantly lessened. The power level of the low power beam cannot be increased in such a device by increasing the output of the laser diode because this would increase the power levels of all of the beams proportionately, raising safety concerns with regard to the beams having the higher power levels.
There is a need, therefore, for a system for producing three light beams on orthogonal, intersecting lines from a single laser diode source which is simple in construction and which provides beams of substantially equal power.